SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd077c1bc201367d086f8c0d20a132bfec69945b1f3333773b95250f6583f7d46' 
  AND token = '80IFyu9Ra/ePurJhoIghH0npzqN8+mBvvfFEk8LKPZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}